Impotence or inability to achieve penile erection is quite prevalent and many solutions have been proposed and are available in the art to cure or compensate for the condition. In particular, various types of penile prostheses are commercially available.
The majority of penile prostheses fall into two types. These two types are the inflatable, implantable prosthesis and the simple implantable inherently stiff or substantially rigid prosthesis. The inflatable prosthesis is normally implanted in pairs within the corpora cavernose and connected to hydraulic pumping means, also implanted within the patient's body, which means enable the prosthesis to be inflated for erection and deflated for flaccidity. The simple or non-inflatable prosthesis is also generally implanted in pairs in the corpora cavernose and, in view of its inherent stiffness, provides a generally constant erection. Hence, it is desirable to provide positionability so that the erection may be at least partially concealed by the patient. Positionability is generally achieved by making the simple prosthesis bendable, and the prosthesis provided by the present invention is of this simple type, herein designated as a mechanical prosthesis.
Some of the mechanical prostheses of the prior art are based upon a rigid but malleable longitudinal core member and these are generally designated as malleable prostheses. Another type of mechanical prosthesis achieves rigidity and positionability through an articulated member and the present invention is concerned with a mechanical prosthesis of this latter type.
U.S. Pat. Nos. 4,151,841 and 4,187,839 disclose implantable penile prostheses having a flexible central longitudinal member.
U.S. Pat. No. 4,665,902 discloses a flexible penile prosthesis having an intermediate tubular section containing a flexible zone. The flexible zone is formed by a plurality of circumferential grooves having sides of unequal length.
U.S. Pat. No. 4,693,719 discloses a penile prosthesis which comprises two or more cylindrical segments which lock into an axially aligned position through the action of a spring plunger.
U.S. Pat. No. 4,790,298 discloses a penile prosthesis having an array of individually pivotable segments which can be rendered into a rigid unit by engagement with interfering members.
U.S. Pat. Nos. 4,151,840, 4,517,967, 4,522,198, 4,541,420, 4,545,081, 4,619,251 and 4,881,531 disclose prostheses utilizing various forms of segmented or articulated structures.
It has now been found that an improved mechanical penile prosthesis of the type having an articulated structure with improved positionability, improved performance and low cost is provided as hereinafter described.